1. Field
The present disclosure relates to an organic light emitting diode (OLED) display device and a method of fabricating the same, and more particularly, to an OLED display device having an integrated secondary battery capable of applying a voltage to a display panel, and a method of fabricating the same.
2. Description of the Related Technology
The cathode-ray tube (CRT) has been superseded by a flat panel display device (FPD) that can be fabricated to be lightweight and thin. Typical examples of the FPD include a liquid crystal display device (LCD) and an organic light emitting diode (OLED) display device. The OLED display device typically has a higher luminance and a wider viewing angle than the LCD, and may be made ultrathin since it typically does not need a backlight.
In the OLED, electrons and holes may be injected through a cathode and an anode and recombine in an organic thin layer to form excitons. Thus, the OLED emits light in a specific range of wavelengths determined by the energy created by the excitons.
The OLED display device may be classified into a passive matrix (PM) type and an active matrix (AM) type, depending on the driving method. The AM-type OLED display device may include a circuit that uses a thin film transistor (TFT). The PM-type OLED display device may be easily fabricated since the display region may include a simple matrix-type device with anodes and cathodes. However, the application range of the PM-type OLED display device is typically restricted to low-resolution, small-sized display devices because of the problems of resolution, the rise in driving voltage, and shortened life spans of materials. In the AM-type OLED display device, each pixel of a display device may include a TFT so that a constant amount of current can be supplied to each pixel to obtain stable luminescence. Also, since the AM-type OLED display device typically consumes low power, the AM-type OLED display device can realize high-resolution, large-sized display devices.
FIG. 1 is a plan view of a display panel portion of an OLED display device.
Referring to FIG. 1, a display panel portion 100 of the OLED display device can include a display panel 160 having a plurality of pixels, an upper power supply line 110, which is disposed above the display panel 160 and applies a power supply voltage VDD, a lower power supply line 130, which is disposed below the display panel 160 and applies the power supply voltage VDD, a reference voltage line 120, which is disposed on one side of the display panel 160 and applies a reference voltage VSS, a scan driver 140, which is disposed on the other side of the display panel 160 and outputs a scan signal, and a data driver 150, which is disposed below the lower power supply line 130 and applies a data signal to the display panel 160.
The display panel 160 may include a plurality of pixels (not shown) formed in regions that may be defined by a plurality of scan lines (not shown) and a plurality of data lines (not shown). Each of the pixels may include a combination of red (R), green (G), and blue (B) sub-pixels and may receive the data signal and the scan signal from the data line and the scan line, respectively.
The upper and lower power supply lines 110 and 130 may transmit a constant power supply voltage VDD to the pixels of the display panel 160. Thus, the upper and lower power supply lines 110 and 130 may be connected to the pixels of the display panel 160 and can apply the power supply voltage VDD from an external power supply to the pixels. The upper and lower power supply lines 110 and 130 may be internally connected to each other. Although the upper and lower power supply lines 110 and 130 may receive separate voltages and apply the voltages to the pixels, the upper and lower power supply lines 110 and 130 generally receive the same voltage and apply the voltage to the pixels.
The data driver 150 applies the data signal to the pixels through the data lines and the scan driver 140 applies the scan signal to the pixels through the scan lines, so that the pixels can be driven.
The display panel portion 100 of the OLED display device can receive the power supply voltage VDD from the external power supply and apply the power supply voltage VDD to the pixels. In this case, since the voltage applied from the external power supply can differ from the voltage to be applied to the pixels, the OLED display device can require an additional voltage controller, such as a DC-DC converter. As a result, the circuit configuration of the OLED display device can become complicated.